Patent DE-102012000462-A1 (DE)
Title: Resistance welding of workpieces in which force applied to electrode is controlled and/or regulated, comprises changing, controlling, regulating and/or modulating force applied to electrodes before and/or after welding process
Inventor: KARAKAS ERDOGAN
IPC: B23K11/24
Filed: 2012-01-13
Abstract: The method comprises changing, controlling, regulating and/or modulating a force applied to electrodes (11, 12) before and/or after the welding process, during the welding process and/or welding as a function of measured and/or calculated welding parameters, process parameters, workpiece parameters and/or secondary circuit parameters of a welding device. The welding parameters are amplitudes, temporal courses, analogous, discrete-time values, average values, effective values and/or their products of welding current, a current density, welding time, and a voltage. The method comprises changing, controlling, regulating and/or modulating a force applied to electrodes (11, 12) before and/or after a welding process, during the welding process and/or welding as a function of measured and/or calculated welding parameters, process parameters, workpiece parameters and/or secondary circuit parameters of a welding device. The welding parameters are amplitudes, temporal courses, analogous, discrete-time values, average values, effective values and/or their products of welding current, a current density, a welding time, a voltage, a calculated and/or measured electric power, a resistor between the electrodes and/or a workpiece and the electrode, plunging the electrodes, an electrode force, a temperature of the electrodes, the workpieces and/or a contact surface of the electrode on the workpiece. The process parameters are lens size, deterioration degree of the electrodes, a current density, a resistor, a temperature of the workpiece, a number of welding points, a tool life quantity, a spacing of the welding points, a shunt, and/or behaviors of the electrode arms. The workpiece parameters are workpiece thickness, a type of material, a material resistance, and/or a material surface treatment, a material temperature, transition resistances and/or a number of workpieces to be welded. The secondary circuit parameters of the welding device are secondary circuit impedance, an electrode shape, a shape of the electrode arms, and/or electrode caps. Reduction of the force per unit area caused by an erosion of the electrodes and increasing a contact surface at electrode contact surfaces is compensated by increasing the force as a function of the measured current, the current density, the current adjusted by stepper function and/or as a function of the measured entire resistor, the power, and/or voltage between the electrodes and the workpiece and the workpiece contacting the electrode. The current, the current time and the welding time are increased, reduced and/or changed (automatic stepper function). The force, the current and/or welding time are adjusted, regulated and/or altered as a function of the lens size, an electrode immersion, and/or the resistor between the electrodes and the workpiece. An independent claim is included for a device for resistance welding of workpieces in which a force applied to an electrode is controlled and/or regulated.